U.S. patent number 5,980,524 [Application Number 08/867,071] was granted by the patent office on 1999-11-09 for device for repairing a meniscal tear in a knee and method.
This patent grant is currently assigned to Innovasive Devices, Inc.. Invention is credited to Daniel F. Justin, Thomas F. Winters.
United States Patent |
5,980,524 |
Justin , et al. |
November 9, 1999 |
Device for repairing a meniscal tear in a knee and method
Abstract
A fastener for use in soft tissue repair includes a resorbable
polymer or suture core having one or more collagen bands in
surrounding relation to the core. The bands are expandable between
a dehydrated state for insertion and a hydrated state for healing,
and are dimensioned and positioned to bring two sides of a tear
into apposition to promote healing of the tear. The fastener
insertion method includes driving an elongated tube across the
tear, inserting a fastener down the tube until it breaches the
tears and removing the tube, leaving the fastener in position to
expand and promote healing of the tear.
Inventors: |
Justin; Daniel F. (Logan,
UT), Winters; Thomas F. (Winter Park, FL) |
Assignee: |
Innovasive Devices, Inc.
(Marlborough, MA)
|
Family
ID: |
25349025 |
Appl.
No.: |
08/867,071 |
Filed: |
June 2, 1997 |
Current U.S.
Class: |
606/75; 606/213;
606/327; 606/331; 606/76; 606/77; 606/908; 606/910 |
Current CPC
Class: |
A61B
17/064 (20130101); A61B 17/068 (20130101); A61B
2017/00004 (20130101); A61B 2017/0646 (20130101); Y10S
606/91 (20130101); Y10S 606/907 (20130101); Y10S
606/916 (20130101); Y10S 606/908 (20130101); A61B
2017/0647 (20130101) |
Current International
Class: |
A61B
17/068 (20060101); A61B 17/064 (20060101); A61B
17/00 (20060101); A61B 017/56 () |
Field of
Search: |
;606/75,72,73,77,76,213,215,219 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Kevin R. Stone, M.D., William G. Rodkey, D.V.M., Richard J. Webber,
PH.D., Luann McKinney, D.V.M. and J. Richard Steadman, M.D., Future
Directions--Collagen-Based Prostheses for Meniscal Regeneration,
Clinical Orthopaedics and Related Research, No. 252, Mar. 1990, pp.
129-135..
|
Primary Examiner: Tucker; Guy V.
Attorney, Agent or Firm: Allen, Dyer, Doppelt, Milbrath
& Gilchrist, P.A.
Claims
What is claimed is:
1. A fastener for repairing a tear in soft tissue of a patient, the
fastener comprising:
an elongated core having:
a distal portion having a narrowing cross section toward a pointed
distal end, for facilitating an insertion of the fastener into soft
tissue; and
a central portion having at least one narrowed region extending
between a proximal end and the distal portion; and
at least one collagen band positioned in surrounding relation to at
least part of the core central portion, the collagen band
expandable between a dehydrated state for insertion and a hydrated
state for healing being shaped to bring two opposing sides of the
tear into apposition for promoting healing and to form an
interference fit between the fastener and the soft tissue for
retaining the fastener in position.
2. The fastener recited in claim 1, wherein the core further has a
proximal portion extending from the proximal end to a proximal end
of the core central portion having a radius larger than a radius of
the narrowed region.
3. The fastener recited in claim 1, wherein the core distal portion
comprises a conical shape.
4. The fastener recited in claim 1, wherein the core material
comprises a plastic biocompatible with the soft tissue of the
patient and further is biodegradable within a first time span
greater than or equal to a second time span over which the sides of
the tear can knit together.
5. The fastener recited in claim 1, wherein the collagen comprises
a cross-linked bovine collagen.
6. The fastener recited in claim 2, wherein the collagen band has a
thickness at a distal end approximately equal to a difference
between the radius of the core narrowed resin and a radius of a
proximal end of the core distal portion, thereby forming a
generally smooth outer surface for facilitating insertion.
7. A fastener for repairing a tear in soft tissue of a patient, the
fastener comprising:
an elongated core having:
a first conical portion having a narrowing cross section toward a
distal end, for facilitating an insertion of the fastener into soft
tissue by the narrowed distal end;
a second conical portion having a narrowing cross section toward a
proximal end of the first conical portion; and
a narrowed central portion extending between a proximal, end and
the second conical portion;
a first collagen band positioned in surrounding relation to the
core central portion; and
a second collagen band positioned in surrounding relation to at
least a distal section of the second conical portion;
wherein the first and the second collagen bands are expandable
between a dehydrated state for insertion and a hydrated state for
healing, wherein the first and the second collagen bands when
hydrated bring two opposing sides of the tear into apposition for
promoting healing and further form an interference fit with the
soft tissue, for retaining the fastener in position.
8. The fastener recited in claim 7, wherein the first and the
second collagen bands each have a thickness adapted for forming a
generally smooth outer surface for facilitating insertion.
9. The fastener recited in claim 7, wherein the core further has a
proximal portion extending from the proximal end to a proximal end
of the core central portion having a radius larger than the central
portion radius.
10. The fastener recited in claim 7, wherein the core material
comprises a plastic biocompatible with the soft tissue of the
patient and further is biodegradable within a first time span
greater than or equal to a second time span over which the sides of
the tear can knit together.
11. The fastener recited in claim 7, wherein the collagen comprises
a cross-linked bovine collagen.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to surgical devices and methods for
repairing tissue tears and, more particularly, to a device and
method for repairing a meniscal tear in a knee.
2. Description of Related Art
The menisci of the knee are C-shaped disks of cartilaginous tissue
interposed between the condyles of the tibia and the femur. They
are actually extensions of the tibia that serve to deepen the
articular surfaces of the tibial plateau to accommodate better the
condyles of the femur (see FIG. 1). The material of the menisci is
collagenous, and the fibers are oriented generally
circumferentially.
As the menisci were long considered functionless remains of leg
muscle, injury to this tissue had been treated by their total
removal, called meniscectomy. A better understanding of these
structures, combined with improvements in arthroscopic surgical
techniques, has led to the development of meniscal repair
techniques.
Posterior peripheral tears of the menisci may be treated by an open
technique, wherein sutures are placed along the tear. An
arthroscopic technique may also comprise placing sutures along the
tear, but in this method through a cannula.
There are a number of fastener-type devices that are known in the
art. A surgical fastener is disclosed by Screiber (U.S. Pat. No.
4,873,976) that comprises a shaft having at least one barb for
locking the shaft in place when inserted into soft tissue. Also
described is an applicator consisting of a cylinder into which the
fastener is placed and out of which the fastener is pushed when
positioned at the tear site.
Bays et al. (U.S. Pat. Nos. 4,884,572 and 4,895,148) describe a
surgical-repair tack and applicator and method of using them. The
tack has a barb member and is made of biodegradable material having
a degradation time selected to coincide with the healing time of
the tissue. In an alternate embodiment, the tack's barb comprises a
continuous helical barb.
The method and apparatus for repairing a meniscal tear disclosed by
Winters (U.S. Pat. No. 5,059,206) comprises a fastener having
protrusions or barbs that is applied to a meniscal tear with a
delivery device. The delivery device has a flexible tip that is
manipulable through a curved radius to enable the surgeon to insert
the device into the central part of the knee and then extend the
fastener radially outward into and across a meniscal tear.
A fastener, driving device, and method have been described by
Justin and Winters (U.S. Pat. Nos. 5,569,252 and a later issued
patent) wherein the fastener has a helical protrusion that is
advanced across a tear in a screwing motion. In the latter patent,
the protrusion has a variable-pitch for bringing two sides of the
tear into apposition as the fastener is advanced across the tear.
The fastener material preferably is a bioabsorbable, biocompatible,
nontoxic plastic that is specifically designed to bioabsorb
generally within the time span of the healing process. A delivery
device for introducing the fastener was also provided that includes
an elongated needle rotationally coupled with the fastener.
Stone et al. (Clin. Orthopaed. Rel. Res., No. 252, March 1990)
introduced a resorbable collagen template for induced meniscal
regeneration.
No method of repairing meniscal tissue with a device made from a
core of bioabsorbable material and outer tubes or bands of
expanding collagen is known to have been disclosed, however.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a bioabsorbable
fastener and method for repairing a tear in soft tissue.
It is a further object to provide such a fastener that is made from
a nontoxic, biocompatible, bioabsorbable material.
It is an additional object to provide such a fastener having a
shape designed to compress the tear.
It is another object to provide such a fastener shaped to resist
forces tending to pull apart the tear during the healing
process.
It is yet a further object to provide such a fastener that expands
following introduction across the tear.
These and other objects are attained with the fastener and method
of the present invention. The fastener of the present invention is
designed for repairing a tear in soft tissue of a patient, a
particular exemplary embodiment comprising a meniscal tear in a
knee.
The fastener in a first embodiment comprises an elongated core that
has a distal portion that has a narrowing cross section toward a
pointed distal end. Such a shape is for facilitating an insertion
of the fastener into soft tissue. The core also has a narrowed
central portion that extends between the proximal end and the
distal portion.
The fastener additionally comprises a collagen band that is
positioned in surrounding relation to the core's central
portion.
The collagen band is expandable between a dehydrated state for
insertion and a hydrated state for healing. This collagen band is
preferably shaped to bring two opposing sides of the tear into
apposition, which promotes healing. The swelling caused by
hydration creates an interference fit between the fastener and the
soft tissue, which retains the fastener in position and resists a
force tending to remove it therefrom.
In a preferred embodiment, the core material comprises a material
that is biocompatible with the soft tissue of the patient and has a
rigidity sufficient to support movement. The polymer core material
is specifically designed to be biodegradable within a first time
span greater than or equal to a second time span over which the
sides of the tear can knit together. This feature permits the
fastener to remain in place for as long as required for the tear to
heal, but ultimately to be bioabsorbed and be dissipated harmlessly
into the patient's system.
Alternatively, the core material comprises suture material that is
bioresorbable.
In another embodiment the fastener comprises a unitary material,
such as only rigid polymer or only collagen, and has means at the
distal and proximal ends for holding the two sides of the tear in
apposition. Such means may comprise barb-shaped protrusions or
split sections that are biased to flare open when not under
tension.
The method of the present invention is for repairing a tear in soft
tissue of a patient. The method comprises the steps of driving a
trocar across the tear in a direction generally normal to the tear
and passing a tube over the trocar to a position wherein the tube
breaches the tear. Next the trocar is removed from the soft tissue.
A fastener containing collagen, or some other expandable polymer,
such as described above in a dehydrated state is then introduced
into the tube and pushed to a position adjacent a distal end of the
tube. Next the tube is removed from the soft tissue, leaving the
fastener in position to breach the tear.
The fastener is permitted to hydrate in situ, which causes the
collagen band to swell, bringing the opposing sides of the tear
into apposition and forming an interference fit between the
fastener and the soft tissue. As described above, this serves to
retain the fastener in position.
In one of the embodiments of the fastener described above, which
comprises a rigid polymer without collagen, after positioning, the
shape of the fastener holds the two sides of the tear together.
The features that characterize the invention, both as to
organization and method of operation, together with further objects
and advantages thereof, will be better understood from the
following description used in conjunction with the accompanying
drawing. It is to be expressly understood that the drawing is for
the purpose of illustration and description and is not intended as
a definition of the limits of the invention. These and other
objects attained, and advantages offered, by the present invention
will become more fully apparent as the description that now follows
is read in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the anatomy of a human knee in cross section,
showing a tear in the medial meniscus.
FIG. 2 is a perspective side view of a first embodiment of the
fastener having a rigid polymer core and one collagen band in a
dehydrated state.
FIG. 3 is a perspective side view of the embodiment of FIG. 2 in a
hydrated state.
FIG. 4 is a perspective side view of a second embodiment of the
fastener having a rigid polymer core and two collagen bands in a
dehydrated state.
FIG. 5 is a perspective side view of the embodiment of FIG. 4 in a
hydrated state.
FIG. 6 is a perspective side view of a third embodiment, an
all-collagen fastener with barbs, in a dehydrated state.
FIG. 7 is a perspective side view of the embodiment of FIG. 6 in a
hydrated state.
FIG. 8 is a perspective side view of a fourth embodiment, an
all-collagen fastener with cut ends, in a dehydrated state.
FIG. 9 is a perspective side view of the embodiment of FIG. 8 in a
hydrated state.
FIG. 10 is a perspective side view of the rigid polymer core of a
fifth embodiment of a fastener.
FIG. 11 is a perspective side view of the embodiment of FIG. 10
with two spaced-apart collagen bands.
FIG. 12 is a perspective side view of a sixth embodiment, a
fastener comprising resorbable suture material with two collagen
rings at each end.
FIG. 13 illustrates a front-side perspective view of the third
embodiment of the fastener being inserted into a delivery
device.
FIGS. 14 schematically illustrates the method of introducing the
fasteners of the present invention. FIG. 14A shows the cannula and
trocar insertion; FIG. 14B the trocar removal; FIG. 14C the implant
insertion; and FIG. 14D the cannula removal.
FIG. 15 illustrates a trocar being driven across the tear and a
tube being passed over the trocar.
FIG. 16 illustrates the second embodiment of the fastener being
pushed down the tube and across the tear.
FIG. 17 illustrates the second embodiment of the fastener in place
in a hydrated state, bringing the two sides of the tear into
apposition.
FIG. 18 illustrates the fourth embodiment of the fastener being
pushed down the tube and across the tear.
FIG. 19 illustrates the fourth embodiment of the fastener in place
in the flared state, bringing the two sides of the tear into
apposition.
FIG. 20 illustrates an alternate embodiment of the method, with the
soft tissue being pierced by the distal end of the fastener.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description of the preferred embodiments of the present invention
will now be presented with reference to FIGS. 1-20.
The preferred exemplary embodiments of the present invention
comprise a fastener and method for repairing a knee meniscal tear
in a human patient. FIG. 1 illustrates a cross section of a human
knee, showing the medial MM and lateral LM menisci and a tear T in
the medial meniscus MM, the tear T having two sides S1 and S2.
The Fastener
A first embodiment of the fastener of the present invention is
shown in FIGS. 2 and 3. The fastener 10 comprises an elongated core
12 that has a distal portion 124 that has a narrowing cross section
toward a pointed distal end 122. This pointed distal end 122
facilitates the insertion of the fastener 10 into soft tissue.
Preferably the distal portion 124 is conical in shape.
A narrowed central portion 126 extends between the proximal end 121
and the distal portion 124.
The core 12 further has a proximal portion 125 that extends from
the proximal end 121 to a proximal end 127 of the core central
portion 126. The proximal portion 125 has a radius that is larger
than the central portion's radius.
A band 14 of polymer that expands upon hydration is positioned in
surrounding relation to the core's central portion 126. Preferably
the collagen band 14 has a thickness 144 at a distal end 142 that
is approximately equal to the difference between the radius 129 of
the core's central portion 126 and the radius 130 of the proximal
end 123 of the core's distal portion 126. These dimensions form a
generally smooth outer surface, which facilitates insertion.
The collagen band 14 is expandable between a dehydrated state for
insertion (FIG. 2) and a hydrated state (FIG. 3) for healing. The
band 14 is also shaped to bring two opposing sides S1,S2 of the
tear T into apposition, which promotes healing and forms an
interference fit between the fastener 10 and the soft tissue MM for
retaining the fastener 10 in position.
An exemplary embodiment of the shape of the collagen band 14
comprises a generally hourglass-shaped band, which under hydration
swells to a bilobed band 14' for compressing the tear T.
A preferred band polymer in this and the other of the following
alternate embodiments comprises collagen; in a most preferred
embodiment the collagen comprises a cross-linked bovine
collagen.
The core material in this embodiment comprises a collagen or a
bioabsorbable plastic biocompatible with the soft tissue of the
patient. (A similar material will be intended when a noncollagen
polymer is referred to.) Exemplary materials include a nontoxic
blend of polycaprolactone and polyglycolide, a blend of polylactide
and polyglycolide, pure polydioxanone, poly(ethylene oxide):
poly(butylene terephthalate), polyorthoester, polyhydroxybutyrate,
or cross-linked collagen. The material is designed to be
sufficiently flexible and strong to withstand natural knee movement
during healing. The material is also designed to be biodegradable
within a first time span greater than or equal to a second time
span over which the sides S1,S2 of the tear T can knit together. In
other words, the material is resorbed over a time span commensurate
with the healing process, so that, once the tear T is healed, the
fastener can gradually degrade, leaving a healed meniscus with no
foreign material embedded therein.
In a second embodiment, the fastener 30 comprises an elongated core
32 that has a first conical portion 326 that has a narrowing cross
section toward the distal end 322. As previously, the fastener's
insertion into soft tissue is facilitated by this narrowed distal
end 322.
The core 32 also has a second generally conical portion 328 that
has a narrowing cross section toward the proximal end 327 of the
first conical portion 326. A narrowed central portion 330 extends
between the proximal end 321 and the second conical portion 328.
The core 32 further has a proximal portion 350 that extends from
the proximal end 321 to a proximal end 331 of the core's central
portion 330. This proximal portion 350 has a radius 352 that is
larger than the central portion's radius 332.
A first collagen band 33 is positioned in surrounding relation to
the core's central portion 330, and a second collagen band 34 is
positioned in surrounding relation to at least a distal section 329
of the second conical portion 328. Preferably the collagen bands
33,34 have a thickness adapted for forming a generally smooth outer
surface of the fastener 30, which facilitates insertion.
As with the first embodiment, the collagen bands 33,34 are
expandable between a dehydrated state (FIG. 4) for insertion and a
hydrated state (FIG. 5) for healing. In this embodiment the
collagen bands 33,34 when hydrated form a bilobed structure that
serve to bring the two opposing sides S1,S2 of the tear T into
apposition for promoting healing and also form an interference fit
with the soft tissue MM, which assists in retaining the fastener 30
in position.
A third embodiment of the fastener 50, which is illustrated in
FIGS. 6 and 7, has a first generally conical portion 51 that
narrows toward the distal end 502, which has a pointed tip 506.
Fastener 50 also has a second generally conical portion 52 that is
proximal of and narrows toward the first conical portion 51. In a
preferred embodiment, the fastener 50 further has a fifth generally
conical portion 55 that is proximal of and narrows toward the
second conical portion 52.
Fastener 50 has at its proximal end 501 a third generally conical
portion 53 that narrows toward the proximal end 501, a fourth
generally conical portion 54 that is distal of and narrows toward
the third conical portion 53, and a sixth generally conical portion
56 is distal of and narrows toward the fourth conical portion
54.
A narrowed, generally cylindrical central portion 58 extends
between the fifth 55 and the sixth 56 conical portions. In a
preferred embodiment, narrowed, generally cylindrical central
portions 512, 525, 534, 546 extend between, respectively, conical
portions 51-52, 52-55, 53-54, 54-56.
Preferably the fastener 50 comprises a polymer that expands upon
hydration, such as the collagen material discussed previously. The
fastener material is expandable between a dehydrated state (FIG. 6)
for insertion and a hydrated state (FIG. 7) for healing. In use the
expanded hydrated conical portions bring the two opposing sides
S1,S2 of the tear T into apposition and form an interference fit
within the soft tissue MM to resist a removal of the fastener 50
therefrom, as the conical portions form barblike protrusions that
tend to anchor the fastener 50 within the tissue T.
A fourth embodiment of the invention, which is illustrated in FIGS.
8 and 9, comprises an elongated generally cylindrical fastener 70,
which comprises a biocompatible polymer. Fastener 70 has a first
distal portion 71 that narrows toward a distal end 702, wherein the
narrowed distal end 702 facilitates insertion into the soft tissue
T. Similarly, the fastener 70 has a second distal portion 72 that
extends in a proximal direction from the first distal portion
71.
A first distal slit 73 extends generally longitudinally from the
distal end 702 into the second distal portion 72; a second distal
slit 74 extends generally longitudinally from the distal end 702
into the second distal portion 72, the second distal slit 74
generally normal to the first distal slit 73. Thus the first 73 and
the second 74 distal slits form four quarter-cylindrical distal
sections 711-714.
Fastener 70 additionally has a proximal portion 76 that extends
from the proximal end 701 in a distal direction.
A first proximal slit 77 extends generally longitudinally from the
proximal end 702 into the proximal portion 76; a second proximal
slit 78 similarly extends generally longitudinally from the
proximal end 701 into the proximal portion 76, the second proximal
slit 78 generally normal to the first proximal slit 77. Thus the
first 77 and the second 78 proximal slits form four
quarter-cylindrical proximal sections 761-764.
The construction of the fastener 70 biases it to expand via the
distal 73,74 and the proximal 77,78 slits between an insertion
position (FIG. 8) wherein the distal sections 711-714 and the
proximal sections 761-764 are closely opposed and a healing
position (FIG. 9) wherein the distal sections 711-714 and the
proximal sections 761-764 are flared. This flared position serves
to bring two sides S1,S2 of a tear T into apposition, which
promotes healing and further to forms an interference fit within
the soft tissue MM to resist a removal of the fastener 70
therefrom.
A fifth embodiment of a fastener 20 comprises an elongated core 22
(FIG. 10) that has a distal conical portion 226 that has a
narrowing cross section toward the distal end 222. As previously,
this shape is for facilitating an insertion of the fastener 20 into
soft tissue.
The core 22 also has a first narrowed generally cylindrical portion
228 that is adjacent and proximal of the distal portion 226. This
portion 228 has a diameter less than the diameter of the proximal
end 227 of the distal portion 226.
A widened generally cylindrical central portion 230 is situated
adjacent and proximal of the first cylindrical narrowed portion
228. This portion 230 has a diameter larger than that of the first
cylindrical portion 228.
A second narrowed generally cylindrical portion 232 is situated
adjacent and proximal of the central portion 230. This portion 232
has a diameter less than that of the central portion 230.
Finally, a widened generally cylindrical proximal portion 234 is
situated adjacent and proximal of the second cylindrical narrowed
portion 232. This portion 234 has a diameter larger than that of
the second cylindrical portion 232.
The first and the second narrowed portions 228,232 can thus be seen
to form generally annular notches in the core 22.
Preferably the core 22 material comprises a plastic that is
biocompatible with the soft tissue MM of the patient and further is
biodegradable within a first time span greater than or equal to a
second time span over which the sides S1,S2 of the tear T can knit
together.
The fastener 20 additionally comprises (FIG. 11) a first collagen
band 24 that is positioned in surrounding relation to the first
cylindrical narrowed portion 228. Further, a second collagen band
26 is positioned in surrounding relation to the second cylindrical
narrowed portion 232. As with previous embodiments of the fastener,
the first and the second collagen bands 24,26 are expandable
between a dehydrated state for insertion and a hydrated state for
healing, and the first and the second collagen bands when hydrated
bring two opposing sides S1,S2 of the tear T into apposition for
promoting healing and further form an interference fit with the
soft tissue MM, again retaining the fastener 20 in position.
Preferably the first and the second collagen bands 24,26 each have
a thickness adapted for forming a generally smooth outer surface,
which also facilitates insertion. Also preferably, the collagen
comprises a cross-linked bovine collagen.
A sixth embodiment 40 (FIG. 12) of a fastener comprises an
elongated bioresorbable core 42 that preferably comprises a suture
material.
Situated in surrounding relation to the core 42 are four generally
conical bands, two 43,44 having a narrowing cross section toward
the distal end 402 and two 45,46 having a narrowing cross section
toward the proximal end 404. The distal band 43 is positioned in
surrounding relation to a distal end (not shown) of the core 42;
the proximal band 46 is positioned in surrounding relation to a
proximal end (not shown) of the core 42.
A third band 44 is positioned in surrounding relation to the core
42 proximal of and in spaced relation to the distal band 43, and a
fourth band 45 is positioned in surrounding relation to the core 42
distal of and in spaced relation to the proximal band 46. The third
44 and the fourth 45 bands are separated by a length of core 42
sufficient to breach the tear T.
The bands 43-46 each comprise a material expandable between a
dehydrated state for insertion and a hydrated state for healing,
for example, a collagen material such as bovine collagen.
The Fastener Insertion Method
The fastener insertion method of the present invention comprises a
series of steps that are generally similar irrespective of which of
the above-described fasteners containing collagen 10,20,30,40,50,70
is utilized. A device 80 for inserting a fastener, shown as
fastener 50, is illustrated in FIG. 13. The fastener 50 is shown
being placed inside the bore 802 of a cannula tube 80. A
scissors-like action of the device handles 81,82 pushes the
fastener 50 out of the bore for delivering the fastener 50 across a
tear T.
Schematically the method is illustrated in FIGS. 14A-D: A cannula
92 having a pointed trocar 90 within its bore is driven across a
tear T in a meniscus MM (FIG. 14A) . The trocar 90 is removed from
the surgical site (FIG. 14B). The fastener 30 is inserted down the
cannula 92 (FIG. 14C) until it breaches the tear T. Then the
cannula 92 is removed (FIG. 14D) , leaving the fastener 30 across
the tear T.
Next the method will be discussed and is illustrated (FIGS. 15-19)
in greater detail with the second embodiment of the fastener 30 as
an exemplary embodiment.
The first step of the method comprises driving a trocar 90, which
typically comprises an elongated pointed instrument, across the
tear T in a direction generally normal to the tear T (FIG. 15).
Next a tube 92 is passed over the trocar 90 to a position wherein
the tube 90 breaches the tear T. Then the trocar is removed from
the soft tissue MM.
A fastener 30 in a dehydrated state is introduced into the tube 92
and pushed to a position adjacent the tube's distal end 902 (FIG.
16). Next the tube 92 is removed from the soft tissue MM, leaving
the fastener 30 in position to breach the tear T.
Finally, the fastener 30 is permitted to hydrate in situ, which
causes the collagen bands 33,34 to swell, forming a structure
similar to a dumbbell, which brings the opposing sides S1,S2 of the
tear T into apposition and forming an interference fit between the
fastener 30 and the soft tissue MM for retaining the fastener 30 in
position (FIG. 17).
When the fastener 70, which comprises a nonexpandable polymer in a
preferred embodiment, is utilized, the method comprises the same
steps as above for preparing the site, including the trocar
driving, tube positioning, and trocar removal steps (FIG.
14A-D).
For this embodiment, however, when the fastener 70 is passed down
the tube 92 (FIG. 18), the tube 92 provides the means via close
dimensioning for retaining the fastener 70 in the insertion
position while the fastener 70 is being pushed down the tube 92.
Then, when the tube 92 is removed, leaving the fastener 70 in
position to breach the tear T, the distal sections 711-714 and
proximal sections 761-764 flare to the healing position (FIG. 19)
and to hold the two sides S1,S2 of the tear T into apposition as
above.
In yet another embodiment of the method of the present invention, a
trocar is not used; rather, fastener, for example, fastener 30, is
inserted into the cannula bore 922 (FIG. 20), and is supported
adjacent the cannula's distal end 902 with the fastener's pointed
distal end 32 protruding therefrom. A rod 93 may be used to
transmit force to the fastener 30, and the fastener's distal end 32
is used to pierce the tissue and breach the tear T. The following
steps, as shown in FIGS. 16-19, remain substantially the same. A
fastener to be used with this embodiment must have sufficient
rigidity to pierce the tissue; consequently, fastener embodiments
10,20,30,50,70 disclosed herein would be suitable for this
method.
It may be appreciated by one skilled in the art that additional
embodiments may be contemplated, including fasteners, systems, and
methods for repairing other soft tissue tears, such as in the
shoulder.
In the foregoing description, certain terms have been used for
brevity, clarity, and understanding, but no unnecessary limitations
are to be implied therefrom beyond the requirements of the prior
art, because such words are used for description purposes herein
and are intended to be broadly construed. Moreover, the embodiments
of the apparatus and method illustrated and described herein are by
way of example, and the scope of the invention is not limited to
the exact details of construction.
Having now described the invention, the construction, the operation
and use of preferred embodiment thereof, and the advantageous new
and useful results obtained thereby, the new and useful
constructions, and reasonable mechanical equivalents thereof
obvious to those skilled in the art, are set forth in the appended
claims.
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